SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11212a56ad6cae93acfdb192a62d1d4239ce12a4fca0047c4a8ce3c1bb278340' 
  AND token = 'nW3Z/9EOFlE9sDEUjY4a8iymGswTqCVgQgSPYMJQuS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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