SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7aa1c00480d34fbea7c65f18f74aab18efbdfee15e869fd1af8705caa50270b' 
  AND token = 'WTh0y0Ymnmj5rBjqbKq/ji79zmin+UsLYxmf2sD1VO8=' 
  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"
    }
  }
}