SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f0bfffe94fd14d3449ecbcfabf5ffc8ff1b182aa58aa8f5d28aba4287040408' 
  AND token = 'qsRMFW+eGd/7m5CyUTbt1Zb+1YWEC8OWyBzdSpweJC8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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