SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1abfd5a22c9f40ef202055590a6635b46b9845e5b72a8cb3913cfca6a00bde15' 
  AND token = 'Y5IBe67bo8nPBsmvymuo3WeWtv2aMS+qBApAcYamMHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}