SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5b2c43047a64b60ad3b5fd447144f0dc716dc88acb7254586c2cbc102f88fca' 
  AND token = 'ggPzg/XeLs/9rort2KNJqKnAxnPQN6u1S7uYdUyS010=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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