SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4192ca3f31e9fa4cf76546b7843e5c031a1024f08c0161fa5c674d8b8b096a51' 
  AND token = 'gH2ST8ZqVCP+FbbiYGWIKGJhwZDGvwZV3A7kDFndrj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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