SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5c1060ae9aeeb5d0ef1928bba2f5f947a033bb37edf599c58cfb8b8b7db877d' 
  AND token = 'GYcq+HWgKhXVjWEKvTwsHp0+wAF3NlnwDXWOUeFcxqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}