SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e23404e3738f9f32a0bacc86eb4bace89c768920b6d7e0ffc3015077af3bda9b' 
  AND token = 'V/x3vG8grVT1HHHLBhADz+8UpWjNe5OUEXm5m8xw1aY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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