SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'beb072b2839c08c7511b632641290e0f281cf9a5ee327ff5964251af044c1172' 
  AND token = 'tPV1koWsivQuy6E0xnkayUbP9JICCe4ymDnVUDPaktk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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