SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bd4c69df5984d16d0d95b66c91408dd6a1377ee12356f86f63884e4631491b64' 
  AND token = '5i5klOTekNaJUQaaOLB+RhilEx7JzCYXuWA/22U8ozE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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