SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07703eb8cf261222f561adc7534b32cdf79f009eccc7d17bc6763082551c907f' 
  AND token = 'ePnD49kkygo/qpd3dmti73xWDoCdCdZlMO3OixMlpis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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