SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0546016bf1124c4286d2401c81639cf77caaf046b9bf6b5c6e7847470422db37' 
  AND token = 'qG+4rlU8G3u5soF0ZHqSZ9THuLpAP4gn9djrvL3+85k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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