SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7287199ea2168cebc38773e3d163d1064d44a54e3d457cbd0873423c3da680c3' 
  AND token = 'JpNZwSPii9nDOWg1Fy1H9AjIanv8ch4ioIEovQ0stOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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