SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c2aab700dafc47f823c89089e0e7f009151845714a93b3539e6aa623edcf53ed' 
  AND token = 'xlQAshqicWsFIg3cLFBriroWdARVBgGFiVZZZ6u3lLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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