SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '232d63dba0a60c334a8303496f7e3b6a2f9107f5771c091c33b0c8489b529965' 
  AND token = 'SXVL68DxtTpgTQSLVSsFAh8/uXQ9qjWjiUXgQ2WsFgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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