SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '75d94fc37f319800cd1b4e8ec5a1d0201242e047aff1141ede0adf52bb980b06' 
  AND token = 'OLfEb5pjzi6kyUxVnck58cvhtAmeFAwm3nypwlv2Wtk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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