SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e4f226b50fadddbd65bb042ce446960edd5bc741abebbe7cda8b9dfe90919c9' 
  AND token = 'jNVQJUXINelpEr6PpwmtO7n1goYGzYUDDcCAIMfq/qc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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