SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63c37d5ecf1995df759dc054f9ff5a0f6754ddbfd10048a904de67d2840ab4a4' 
  AND token = 'hIjYf/AckXAYntddQZylpmbnJTUbfM3odvLxf8enUfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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