SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dbe9e4fe64bf8d42c62cd8394c1ec3a1a3ff22b60a2fe59b2aa19e16e68ac975' 
  AND token = 'fRrTxU97iFm1zVdzyHFNdzG2dcvNnKum8oHXW+zGmdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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