SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a94a0f49c1d7c10ad4604d12da4aeef97ad3ec2c2a061e1fb9b3d51706f072f1' 
  AND token = 'rWwGdsLO+zmuDqTorHyiokIpILm7zhhgm2zQvU+8UMk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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