SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71143e407a261ffdcb4a23e29331e6d274845372008d01ed1216b03cad7c1bab' 
  AND token = 'bovAqXOOqhAJYx1H54GLN2fRAmtdtNUGIhQlYRx3ZEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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