SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ce5b7b9e56a6bb9d9643b4ea3c5b25a97fe8145de0e0c35bf7c5a98e72fd469' 
  AND token = 'zT7VYaqRWlVD+LYLDvGBsFOGbn6oYykl0Z/CrWHfQD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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