SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47526e2490060bb12f0b4fe9a8a314775ba3b99b3be55557e1f6896bea9ce4b8' 
  AND token = 'zhM8HGhDIvjfgVyuvJYcVWaZW4l4nI0nlMtpslAmFo8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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