SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a24cb3c9064204cfdb0ca9972c9a972c21d6920969e53795f735a04f5450d039' 
  AND token = '5ySHXcJunSIthy0Qd5a9eTndOmjGSe/VqFetWu/bO1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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