SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc23ca34b1f8f509e01b63763c97f45e0b4e42b2be94358ae91eceec927e75e6' 
  AND token = 'jHa6vn/2DXMXJmllpfcEBoxuuiiwCbe8nrp9Dbmxp/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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