SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '032c433ac0d3471c1f74cdc0e99e73639d961439479fefc7ea349358a819a98e' 
  AND token = '1cCAxSNqwaQcNP/aU9JoxovxRmOmZWMJg2oaXOLrJQE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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