SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c6b2a984b125e264d3342d485b262b22c8fef7ea24168e5636d9fd037b774c3a' 
  AND token = 'cDpoKb/BF1hA4H/qLR4qK2wJnsPHDwqzaiU8e03GnY0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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