SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cb27d59b92bc7bb0a5c933bbd536a76fd322b07fd2715de7b709072cd4c4200' 
  AND token = 'tB62+ES17IjjOrOJ1t7+tTxOLc/EcAFQ6UgULLKUY+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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