SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9186116861b6e2cd49cfc39f337db3584162ecccf933436c1c8dee22e2fee9f4' 
  AND token = 'gEvbHoTa0bVlhL+J5prll0EHEKTm4daJjiveqV3RF4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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