SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a91b14502425d1adcc63ad4bcebfc69800c64f4a61f8de7afcd98388790d5f88' 
  AND token = 's37zEy+UzGetFgA/TYqn8l2utuPw8SrO+W3ehuOv2Kk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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