SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0742cabe37cd8c714e2176fc63db00359881787a4108b152d73c9f95a1208582' 
  AND token = 'ERXXuvN3Bi7GMWsuW1R9mMNQLI4GsKPX4hTtyLojE2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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