SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92779c09df3af5219df62765983de17dece94c41f0fcfe66b774b5586fa5fbcb' 
  AND token = '1fJfu6bCYRqKLUnQVcqVQaKGZWZFDH8okWgDI9QbXM4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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