SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2a60693611344147c1b9202018a17e21a7311b6510ae6a168311e9e7bc07e1e' 
  AND token = 'N5vLige6+WaiNskRndmzbkwwXqsPscXVOY8FUVaakK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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