SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b2d4d731f994d542761109c2e27a196eaa74f14b956ac06c473db3663ee02491' 
  AND token = '0CRVhcszKphL2cnLmbmh43drGpHhmC0cU/I7bDgoPn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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