SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17e7506761135703aafd5adcfaffa552d0e3217777b6caa133de0ee6d1987c02' 
  AND token = 'a7D2d9aorizGKQIKYpbH9qChPtMAusCjqeadyd2IHPQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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