SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '464d35c13ad4d7bc56f09fe921617c50512649ceb3bb61b8aadcefeee708b81a' 
  AND token = 'ckLOZfHpaXRGTJc9Tp5PY45C5GqWTa0C6o6CT4uMDHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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