SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54f72ac50637f4490fd8807f94a8524cee1eff208aa2a9b581310ddfc12b4c87' 
  AND token = 'cFiqJcPTJ8RBrcAYA0sDsVKGPT3w3jimlbygOgBrQIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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