SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a7e9738ac5c242fd195bd4e0cf07da2ec7e60d04dc9934bf7716869b5c91633' 
  AND token = 'Dzi/XZwHJcIbObvVC+sliYQ6TRwL/se/GQpPMJdMIXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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