SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7bf24df8b82710a701ed0a4992c51fcd2be087e2049a5063fb09a5c573745a4c' 
  AND token = 'zn8tSy1JSeLWadGxXkJyCsFLpd7TNhpNMbxGkLBmIUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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