SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b95acaa48de8e3c0127e9b81597ca69062edff22718a37289ff72b82de4b6649' 
  AND token = 'McnXXYcElR4bxFjbfYKGxOb5pZoWWP+GDVpNVDcavxQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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