SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d23f0ec8b4b96b9c22814c641497350de49242dc9c6171d1f47ffd8aadc0499' 
  AND token = 'jd791W+vDNPgSLQ1TQBlGuIAyw9dn7012uRDoaro/Xk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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