SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35443167d66cc278e3cbc333c6cfa5ccd63b89bbe8060de16c4a0e6efbd488e7' 
  AND token = 'Gz8bMD1FHGo7cSKfOKegkkaZ4bPL3NYYppqSnp3YBoY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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