SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b250a89b941db9ad82db1ff15685b8ce003a3d70d859034c7c04b551e1dc69b3' 
  AND token = 'JelsQ37ugYm58REBYIMxlBK61CrL9Ujb780rj/U9rhs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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