SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1de55afe364d79fa71783cef4a6967cc575c2b6b896f54e32365f5d4741b221' 
  AND token = 'LnH+9KJkhf1XIfyuvgeOqVGTMJhWFjoaEXMf35ZzbPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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