SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46b725786cf25c618387eed5555908afe0398842e67edfd17551fc5b22d0722c' 
  AND token = 'Aw+e1yIqJ4x96K4WBo1uYVaIuIjDwka76fFrPaf2KZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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