SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c32e322fdebf06201ab16888a072752a0cbdd7b394bef6f3acc63e2ef2d8bc1' 
  AND token = '9Bzt1ir2HXdRpSp190NSnFEZpxgfS/AaeZBRRQ3/tpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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