SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f896a2816bb22a0ecf0d6df57944120d6cfdbfc99a4c5e4b7ee6ff422594919c' 
  AND token = 'sQse/BFiktr3vqykL4e92VtTpuTMUHuA5YjzNqEe3sU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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