SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5ce65f09797044fb67eba03ae6dc9661365b3def3134573aa7de92b8ef20966' 
  AND token = 'B1ydthSSnmKNlR5rmt6KbNrZSjJcphw1E7EvSHmPl/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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