SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e87bc0940715ff6810ba009f40371b17278976ccf823f58def9d1a6fa5adbd11' 
  AND token = 'NPFQ0m0wnmJBjr2Pf3uiGPScjKG6Mb3yxEzILBQn9qU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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