SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a469d515996157968f97671955a52fe6a587a1389d875004ca0b7d83a567ff7a' 
  AND token = 'WUDudZr8qMTLOWiS6gzFzgzQiv/vpwwSKpjgmQdJ3j0=' 
  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"
    }
  }
}