SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd03ca88601119a2b77456787529d4a01d1caefa40e853be1c7971cd89f92ff31' 
  AND token = 'VllWhtdMI3OYZ1fv6yTvww08XVUqOkY6P2/OwyHRUEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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