SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cb8c82ba175f9845c67b47647394fdcf05ea46d2cd3de5f284df310cfe21f7b' 
  AND token = 'D3KYLBvyGD/QbwXVAlc0RK5DS/psC/zAemkYbw+Ey1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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