SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f03fc1033b8e19889331988855306fef3355d3427b2d7b3e17b129e924784763' 
  AND token = 'qm1PnebOCB+2uLD/D6fVniAxIi442jcdxXEn7yxwqJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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