SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae80d175f36dcd993df60d24a490e3a6ab4562e1d3abe99111da661c4736ceaf' 
  AND token = 'hYUY0Lt3XfM2iHTBEIW+2uRz2AeDYYRXso1HJ8zhYgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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