SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fed0a62d4d0e94343d11d88cb61d62871b8b77d27e81d497827044ae7c8d5df4' 
  AND token = 'MWNhMOItFXSUGhCNf85hU5KcE4uh50jAsbGftUQ5TeQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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