SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1133ceba79320255fd573e9751c826418c96380837488aad3aa2c269c663834' 
  AND token = 'KBOF/iol7LbgtClNEEToMIX9gEDJPaJAJERb/Ylo9Xc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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