SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ac951c4cd55c905130dd301d4c27b1695cccb78dfac1da49dd0069d85725845' 
  AND token = '+U4xvp6Kz1Nvy0LPdoaZRRiD0PbYo8+G62SsV/6Y1Ug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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